The first goal of this application is to initiate a Clinical Center for the Full Scale phase of the "African-American Study of Kidney Disease and Hypertension". This study is a cooperative, multicenter, prospective, double-masked, randomized study that will follow a three by two factorial design. This study will be limited to about 900 African-Americans recruited from 14 Clinical Centers. Eligibility for participation will be determined by strict inclusion and exclusion criteria. Only those with seated diastolic blood pressure equal to or more than 95 mmHg and with glomerular filtration rate (GFR) 25 - 70 mmHg/1.73m2, without malignant hypertension or systemic disease and who are willing to cooperate will be considered. This study will consist of three phases: (l) Recruitment (24 months); (2) Intervention and follow-up (45 months); (3) Data analysis, close-out, results reporting (12 months). The second goal of this study is to test whether one of three different initial randomized drugs: angiotensin converting enzyme inhibitor (ACEi), calcium channel blocker (CCB) or beta blocker. better reduces the rate of decline of UFR in African-Americans with renal insufficiency attributed to hypertension. A third goal is to examine if one of two levels of blood pressure control (equal to or less than 92 mmHg vs. 102-107 mmHg, mean arterial pressure) is better at preserving renal function. Assignment to treatment and blood pressure groups will be randomized and the treatment regimen will be double-masked. Subsequent to assignment. no other ACEis, CCBs or beta- blockers will be used. If a blood pressure goal is not reached in a participant on maximal doses of the assigned drugs, additional antihypertensives will be used in the following order: (l) diuretics (furosemide); (2) alpha-blocker (doxazosin); (3) central alpha2 agonist (clonidine); (4) minoxidil or hydralazine. This study has major health related implications for disease prevention in that it will try to examine if renal failure due to hypertension that occurs in an extremely high risk African-American population can be slowed or prevented, thereby reducing the need for dialysis and renal transplantation.